> Yes I believe this affects the compiler as well.  I'd like to fix it, I
> just have to find some time to read some cl- code to understand how to
> distinguish them, the patch should be easy.

For context, here's a WiP patch that doesn't do the above, but is
somewhat related.

For what you describe, I think the better change is to change the
`parents` slot of cl-struct classes so it points either to `cl-structure-object` or
`array` or `list`.

IOW, instead of having hacks to add the right parent when `parents` is
nil, `parents` should "never" be nil (except for the `t` type).


        Stefan